20655972 has 72 divisors (see below), whose sum is σ = 55036800. Its totient is φ = 6772896.

The previous prime is 20655967. The next prime is 20655989. The reversal of 20655972 is 27955602.

20655972 is a `hidden beast` number, since 2 + 0 + 65 + 597 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76654 + ... + 76922.

It is an arithmetic number, because the mean of its divisors is an integer number (764400).

Almost surely, 2^20655972 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20655972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27518400).

20655972 is an abundant number, since it is smaller than the sum of its proper divisors (34380828).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20655972 is a wasteful number, since it uses less digits than its factorization.

20655972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The square root of 20655972 is about 4544.8841569395. The cubic root of 20655972 is about 274.3775320394.

The spelling of 20655972 in words is "twenty million, six hundred fifty-five thousand, nine hundred seventy-two".